Virtualization Blog

I’m using Ubuntu 14.04, and after a power outage I can’t connect to the server. I’ve connected to the server using vsphere web client (but you can do the same through console as well), and ran: ifconfig command, but I didn’t see eth0 at all.

Afterwards I ran the following command: ip link

And I saw that eth0 state is “down”.

Solution:

In order to enable the network adapter I ran: sudo ifconfig eth0 up , and saw that eth0 is back!

Today I tried to power on a vApp in my VCD environment but I get the following errors:

Could not find resource pool for placement of edge gateway e6bac9a3-02f2-4d63-aa1d-0000000000. This is because compute, storage or network requirements are not satisfied by any of the resource pools. The operation failed because no suitable resource was found. Hub “Resources” doesn’t have enough “*” storage: required – 448 MB, available – 0 MB.

Solution:

This is a bug in vCloud Director, in order to work around it please follow the steps below:

Log in to your vCloud Director portal.

Go to Manage and monitor tab -> Datastores & Datastore Clusters.

Right click on the relevant datastore -> Disable
(When you disable a datastore, you cannot start vApps that are associated with the datastore or create vApps on the datastore).

Right click on the relevant datastore-> Properties -> decrease the disk space threshold yellow to 50GB and disk space threshold red to 25GB.

I tried to unallocate a LUN that was previously connected to a *VIO server but I have received the following error: “An error occurred during processing on the storage system (The LDEV is being used by the host, or an error occurred in the VSP procedure) (KAIC06400-E)”

The LUN was removed from the AIX host prior to my attempt to unallocated the LUN.

*VIO= The Virtual I/O Server is software that is located in a logical partition. This software facilitates the sharing of physical I/O resources between client logical partitions within the server. The Virtual I/O Server provides virtual SCSI target, virtual fibre channel, Shared Ethernet Adapter, and PowerVM™ Active Memory Sharing capability to client logical partitions within the system. As a result, client logical partitions can share SCSI devices, fibre channel adapters, Ethernet adapters, and expand the amount of memory available to logical partitions using paging space devices. To make things short it is similar to VMware only provided by IBM to virtual Unix servers.

Solution

The problem was that the LUN (LDEV) that I was trying to unallocate still had SCSI reservation which took ownership on the LUN.

There are two ways to overcome this error:

By connecting to the Server by PUTTY and removed the SCSI reservation on the LUN

By connecting to Storage Manager and remove the SCSI reservation

Connecting to the Server by PUTTY and removed the SCSI reservation on the LUN

Connect to the server by putty

Enter the following command: /usr/DynamicLinkManager/bin/dlmpr –k DISK_NUMBER In order to see if the disk has SCSI reservation

Enter the following command: /usr/DynamicLinkManager/bin/dlmpr –c DISK_NUMBER In order to delete the SCSI reservation

Connecting to Storage Manager and remove the SCSI reservation

Connect to storage navigator

Go to Ports/Host Groups and go to one of the ports that the LUN you are trying to unallocated is connected to

Mark the host name that the LUN is allocated to

Go to LUNs > stand on one of the LUNs > More Actions > View Host Reserved LUNs

Soft zoning uses filtering implemented in fibre channel switches to prevent ports from being seen from outside of their assigned zones. The security vulnerability in soft zoning is that the ports are still accessible if the user in another zone correctly guesses the fibre channel address.

Soft zone concept is that the enforcement relies on the WWN of the node in the fabric.

Soft Zoning means that the FC switch will place a host WWN in a zone, without dealing with the port numbers they’re connected to in the FC switch.

Pros and Cons

Pros:

You can Connect to any port on the switch

Cons:

you will need to know to which port the host is connected to for maintenance purposes

It’s possible that a hacker will attempt to spoof WWN

Hard Zoning

Hard zoning is zoning which is implemented in hardware.

Hard zoning physically blocks access to a zone from any device outside of the zone.

Usually hard zoning is used when using VLANs. You would associate a port into a zone